A Randomized Phase II/III Study of Vorinostat (IND# 71976) and Local Irradiation OR Temozolomide and Local Irradiation OR Bevacizumab (IND# 7921) and Local Irradiation Followed by Maintenance Bevacizumab and Temozolomide in Children with Newly Diagnosed High-Grade Gliomas: A Groupwide Phase II/III Study